Fukbtace



J. H. DUI-IME. FURNAGB.

No. 24,547. Patented Jul-ne 28. 1859.

UNITED STATES PATENT OFFICE.

JOHN H. DUHME, OF CINCINNATI, OHIO.

FURNACE.

Specification of Letters Patent No. 24,547, dated June 28, 1859.

To all whom it may concern.'

Be it known that I, J. H. DUHME, of Cincinnati, county of Hamilton, andState of Ohio, have invented an Improvement in Furnaces for BurningCoal; and I do hereby declare that the following is a full, clear, andexact description of the same, reference being had to the annexeddrawings, making a part of this specification, in which- Figure lrepresents a perspective view, showing the exterior view of a locomotiveboiler and furnace. Fig. 2 is a` transverse section taken through thered lines of Fig. 3. Fig. 3 represents a longitudinal vertical sectionof the furnace showing the interior of the same.

The nature of my invention consists in the arrangement of a Hue spaceunderneath the furnace, and a second behind the furnace front, butbetween it and the fire; each of these iiue spaces being controlled by adamper.

In the use of the several gaseous coals for burning in furnaces for theboilers of locomotives and other engines great difficulty has beenencountered in supplying the tire with the necessary amount ofatmospheric air to support a free combustion of the coal andconsequently to attain an economical degree of heat within the furnace.I entirely obviate this difficulty, and by a simple and cheap attachmentto the furnace, which is applicable to any variety of coalburningfurnace, I place the control of the amount of draft requisite tosupply the furnace, in the hands of the engineer, and bring the freshair under and in direct contact with the lower part of the fire, andcarry it up in front of the fire and pass it up through the whole bodyof the coal contained within the furnace, if necessary.

One of the objects gained by my devices is, to make use of air forsupplying the combustion which air has been previously heated. This isless necessary for the air which passes through the grates underneathand throughout (A) space. But it is more particularly necessary when theair is fed into the fire through the A space, and thence through theholes in plate (C) as seen in Fig. 2. These holes are made to supply airat nearly a red heat, to burn up the smoke and vapors thatescapeunburned from the top of the fuel within the furnace, and which, ifsupplied with cold air entering the holes directly from outside, wouldnot carry in heat enough to set fire to such smoke and vapor. In casehowever of fuel containing little or no combustible vapor, or where lessheat is required than usual, the A space is closed up by a damper H,and4 air is only supplied through the grates underneath the tire, andiue A is also controlled by a damper, G.

' It is not deemed necessary to give a detailed description of either ofthe iue spaces A, A', as they are sutliciently indicated in the drawingsin Figs. 3 and 2, where the former shows the width of the flue spacesand how the perforate plate C, after ascending to the usual height ofthe fuel is bent over in front and riveted to the bottom part of theplate of the door I). Fig. 2, shows the front of plate C, with theperforations c, c, c. The plate, C, is constantly maintained at a redheat, so that the air allowed to pass through must be heated almost tothe same temperature, having had its temperature considerably raised bypassing through A, and still more along A, by the time it reaches thesmall holes c, c, it is hot enough to set fire to any combustible withwhich it may come in contact.

It is well known that in the combustion of bituminous coals in closefurnaces a larger amount of smoke and combustible vapor pass offunburned, and even when cold air is admitted through the furnace front aconsiderable portion of the combustible vapor passes o2 unburned underthe best management.

That I claim as my invention and desire to secure by Letters Patent is,

The arrangement of the flue spaces A, A, controlled by dampers H and G,for the purpose of increasing and perfecting the combustionsubstantially as set forth.

JOHN H. DUHME.

Witnesses:

R. S. CAMPBELL, H. E. CLIFTON.

